About

Dan Gifford is using several large cosmological simulations to test a new dynamical mass estimator for galaxy clusters called the caustic technique. This technique uses the positions and line of sight motions of a cluster’s component galaxies to trace the profile of the underlying dark matter that dominates the mass. These results help inform Gifford and his advisor’s observation strategy for clusters in the real universe. They are currently using the 6.5-meter Magellan telescopes in Chile, along with the 2.4-meter Hiltner telescope to collect data on hundreds of clusters to estimate their masses using the caustic technique. This large sample of cluster masses will put constraints on cosmological parameters and make the caustic technique a valuable alternative to other cluster mass estimators in future surveys.